The mandarin fish – the most colourful fish in the ocean

What Is The Mandarin Fish?

Synchiropus splendens, also known as the mandarin dragonet or the mandarin fish, is a small member of the dragonet species family. It is trendy in the saltwater aquarium trade. The mandarin fish is a native of the Pacific. It can be found from the Ryukyu islands southwards to Australia. It is usually found in warmer waters and ocean waters.

The mandarin fish

Albert William Herre, an American Ichthyologist who worked in the Philippines, first called the mandarin fish Callionymus splendidus. Later, it was placed in the genus Synchiropus. Synchiropus, the generic name, is derived from the Ancient Greek syn, which means “together” and “hand-foot.”

The Latin word for “bright” or “glittering” is the epithet magnificentus. Because of its vivid coloration, the common name for the mandarin fish is “the mandarin fish”, evoking an Imperial Chinese mandarin’s robes.

Some other terms are mandarin goby (green mandarin), striped mandarin fish (green dragonet), striped mandarin fish (striped dragonet), and sometimes psychedelic mandarin fish. The closely related mandarin fish (Siniperca chuatsi), the Chinese perch, is distantly related.

The mandarin fish

Callionymidae’s perciform family, the dragonets (mandarin fish), includes ten genera and more than 182 species. Genus Synchiropus has 51 species. It is divided into ten subgenera. Along with the S. occidentalis (Pterosynchiropus), the mandarin fish is included in Subgenus Synchiropus.

What does the Mandarin Fish Look Like?

S. splendidus, or the Mandarin Dragonet, is one of two vertebrate species with blue coloring due to cellular pigment. The other is the closely related S. picturatus (psychedelic mandarin). Blue chromatophores (or pigment-containing and light-reflecting cells) are the ones that inspired the name “cyanophore.”

The mandarin fish

Blue is structural due to thin-film interference caused by piles of flat, thin, and reflecting purine crystals. Although the Mandarin Dragonet has a similar body to a goby’s, this is the only resemblance. This vivid coloration features a bright blue or azure background with swirly orange stripes. It has a blue-greenish, bluish-blue face with bold blue lines.

The huge pelvic fins used to ‘walk’ on the seafloor are often misunderstood because of the pectoral. Near the middle of the body, the primary pectorals can be seen. They are almost transparent and have an anal fin and a small stripe on the vibrant orange and blue tail. A striking orange-and-blue design is also found on the dorsal fin. This is especially tall for males.

Male mandarin fish
Male mandarin fish with the tall dorsal fin

The eyes are typically red with black pupils. There are many sports, markings, colors, and colors. The most well-known fish is the green Mandarin Dragonet. Red mandarin fish is a similar species.

However, its pelvic fins are orange, and the orange of its eyes is red. Rarely, the entire dragonet may be red with black stripes. The spotted mandarin fish is light grey-green with blue, black & pink spots.

Mandarin Dragonet prefers reefs and is a reef dweller. They are slow-moving and common in their species’ ranges, but they are difficult to see due to their small size (6 cm) and bottom-feeding habits. They eat mainly smaller crustaceans and invertebrates.

The mandarin fish

Mandarin Dragonet Diet

Sadovy and colleagues analyzed seven wild fish guts. (2001) found that mandarin fish eats a mixed diet consisting of small gastropods.

Wild feeding takes place continuously during the day. Fish pick out small prey on coral substrates in their home territory, which is many square meters.

The mandarin fish

Mandarin Dragonet Association With Humans

Despite their popularity in the aquarium trade, Mandarin fish are challenging to care for due to their particular feeding habits.

Some fish resist aquarium life and will not eat live amphipods or copepods. However, individuals who adapt well to aquarium food are highly resilient to diseases like marine ich.

The mandarin fish

Because they don’t have the usual skin type affected by marine ich, they are less likely to get it. Even the Mandarin Dragonet has a bitter and smelly slime layer rather than scales. This helps to prevent disease and discourage predators.

The mandarin fish was featured on two stamps: a 39-kip Laos stamp issued in 1987 and a 40-cent stamp of Federated States of Micronesia, published on 26 August 1993.

The Mandarin Fish Gets Smelly To Defend Itself

Although the Mandarin Dragonet (Synchiropus splendens) is one of the most stunning fish in the ocean, it has so much more to offer than just beautiful colors.

The mandarin fish

At home, within the sheltered lagoons and inshore reefs of the Pacific, starting from the Ryukyu Islands, the shoreline of Japan, to warm Australian waters, this tiny dragonet is covered by small spines to inject a toxic mucus into anyone who tries to handle and eat it.

Two secretory cells are found in the Mandarin Dragonet’s colorful epidermis. One produces thick mucus to protect it against the elements, and another makes a toxin that protects it from predators. This toxic mucus coating can be dangerous – it could cause an open injury to a predator. It also smells horrible.

The mandarin fish

Every scientist and every book that talks about the mandarin fish make mention of its strong smell. This stink isn’t accidental. Mandarin Dragonets need the smell and the spines because they lack one of the most essential protection measures in the marine world: Scales.

It takes nothing to make someone turn away from a potential meal but thick slime and an unpleasant odor.

The mandarin fish

Produces a blue pigment.

It’s not easy to look and smell so good. The mandarin fish is the only confirmed species that can produce the blue color. With its near relation, the psychedelic mandarin (Synchiropus picturatus), the Mandarin Dragonet creates ‘cyanophores’ – blue pigmented, light-reflecting cells – to attain its vibrant coloring.

The mandarin fish

As I mentioned, most blue-hued creatures need to create optical illusions. They use microscopic layers containing colorless crystals in the skin to give off a brilliant blue color to anyone who looks.

Mandarin Dragonet Care Guide:

Mandarin Fish (Mandarin Dragonet) Care Guide: The Most Mesmerizing Fish In The Ocean

Further reading



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